screw and barrel for plastic extruder machine 1.for single screw extruder 2.material:38CrMoAlA 3.Bimetallic ... layer screw and barrel for plastic extruder machine Screw material: 38CrMoAlA(JIS SACM645)Surface Treatment: Nitriding treatment, Hard ... ,120mm,150mm,180mm,200mm screw and barrel for plastic extruder machine